svn commit: r305799 - stable/11/sys/cddl/contrib/opensolaris/uts/common/fs/zfs

[Alexander Motin]

Author: mav
Date: Wed Sep 14 09:12:49 2016
New Revision: 305799
URL: https://svnweb.freebsd.org/changeset/base/305799

Log:
  MFC r305123: Fix kernel panic when inheriting properties without default.
  
  There are two writable hidden properties "iscsioptions" and "stmf_sbd_lu",
  that have no default string value.  Attempt to unset them or replicate
  caused kernel panic.  This simple bandaid seems fixes the problem nicely.

Modified:
  stable/11/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_prop.c
Directory Properties:
  stable/11/   (props changed)

Modified: stable/11/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_prop.c
==============================================================================
--- stable/11/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_prop.c	Wed Sep 14 09:11:03 2016	(r305798)
+++ stable/11/sys/cddl/contrib/opensolaris/uts/common/fs/zfs/dsl_prop.c	Wed Sep 14 09:12:49 2016	(r305799)
@@ -54,6 +54,8 @@ dodefault(zfs_prop_t prop, int intsz, in
 		return (SET_ERROR(ENOENT));
 
 	if (zfs_prop_get_type(prop) == PROP_TYPE_STRING) {
+		if (zfs_prop_default_string(prop) == NULL)
+			return (SET_ERROR(ENOENT));
 		if (intsz != 1)
 			return (SET_ERROR(EOVERFLOW));
 		(void) strncpy(buf, zfs_prop_default_string(prop),